Diesel Jeep Comanche For Sale: A Comprehensive Buyer’s Guide

Diesel Jeep Comanche For Sale: A Comprehensive Buyer’s Guide jeeps.truckstrend.com

The Jeep Comanche (MJ) holds a special place in the hearts of automotive enthusiasts. Born from the rugged DNA of the XJ Cherokee, this unibody pickup truck offered a unique blend of Jeep capability and pickup utility. While factory gasoline engines powered the vast majority of Comanches sold in North America, a niche and highly sought-after variant has emerged: the Diesel Jeep Comanche For Sale. These aren’t factory creations but rather meticulously (or sometimes not-so-meticulously) executed engine swaps, transforming a beloved classic into a torque-rich, fuel-efficient, and undeniably unique off-road or workhorse machine.

For those in the know, finding a Diesel Jeep Comanche for sale is akin to discovering a rare gem. It signifies a fusion of classic American utility with the enduring power and efficiency of a diesel engine, promising a vehicle that stands out from the crowd and delivers a driving experience unlike any other. This comprehensive guide will delve into everything you need to know about these fascinating vehicles, from understanding their appeal to navigating the intricacies of purchasing one.

Diesel Jeep Comanche For Sale: A Comprehensive Buyer’s Guide

The Allure of the Diesel Comanche

Why would anyone go to the trouble of swapping a diesel engine into a Jeep Comanche? The reasons are compelling and rooted in the inherent advantages of diesel power:

• Unmatched Torque: Diesel engines are renowned for their low-end torque, making them ideal for off-roading, crawling over obstacles, and especially for towing. A stock Comanche, while capable, often left owners wanting more grunt for serious work.
• Improved Fuel Efficiency: While not always a dramatic improvement depending on the engine and driving style, diesel engines generally offer better fuel economy than comparable gasoline powerplants, especially for highway cruising or consistent heavy loads.
• Durability and Longevity: Many diesel engines are built to last, often clocking hundreds of thousands of miles with proper maintenance. This aligns perfectly with the robust, long-lasting nature of the Comanche chassis.
• Distinctive Character: The unique rumble of a diesel engine, combined with the classic Jeep aesthetic, creates a vehicle with immense character and curb appeal. It’s a conversation starter wherever it goes.
• Rarity and Exclusivity: Since no factory diesel Comanches were sold in the US, every one you find is a custom build, making them incredibly rare and desirable for collectors and enthusiasts seeking something truly unique.

Understanding the Diesel Swap Phenomenon

The critical distinction when discussing a "Diesel Jeep Comanche For Sale" is that you are almost certainly looking at an engine-swapped vehicle. This is not a factory option you’d find on a dealer lot in the 1980s or 90s. The quality and success of these vehicles hinge entirely on the quality of the engine swap.

Common diesel donor engines for Comanche swaps include:

• Mercedes-Benz OM617: Often sourced from 1970s and 80s Mercedes 300D/SD/TD models, these 5-cylinder turbodiesels are celebrated for their legendary reliability, simplicity, and mechanical fuel injection (meaning fewer electronics to go wrong). They offer respectable power and decent fuel economy, making them a popular choice for a straightforward, dependable swap.
• Cummins 4BT: The "gold standard" for many heavy-duty Jeep and truck swaps, the 4-cylinder 3.9L Cummins 4BT is essentially half of the revered 6BT found in Dodge Ram trucks. It delivers immense torque and power, is incredibly robust, and has a vast aftermarket for parts and upgrades. However, it’s significantly heavier and noisier than other options, and its vibrations can be a challenge to mitigate.
• Volkswagen TDI (various generations): These modern, electronically controlled turbodiesel engines offer excellent fuel economy and surprisingly good power for their size. They are lighter and more refined than the 4BT, but the electronic complexity can make the swap more challenging and require specialized tuning.
• Isuzu 4BD1/4BD2: Found in various commercial trucks, these engines are known for their durability and good power output. They are less common as swap candidates but can make for a robust build.
• Other Swaps: Less common but possible are swaps using smaller Kubota engines for ultra-efficiency, or even more modern Cummins/Duramax/Powerstroke engines for high-performance builds, though these often require extensive frame and drivetrain modifications.

The implications of buying a swapped vehicle are significant: you’re not just buying a truck; you’re buying someone else’s engineering project. The quality of the swap dictates everything from reliability to drivability and even legality.

Key Considerations When Buying a Diesel Comanche

Purchasing a swapped vehicle requires a different mindset than buying a stock one. Due diligence is paramount.

1. Engine Type and Condition:

   • Which diesel? Understand the characteristics of the specific engine used (OM617, 4BT, TDI, etc.). Each has its pros and cons regarding power, noise, reliability, and parts availability.
   • Engine Mileage vs. Chassis Mileage: The engine may have far fewer or far more miles than the truck’s odometer indicates. Ask for engine service records.
   • Visible Issues: Check for excessive smoke (black, white, or blue), unusual knocking or ticking noises, oil leaks, and coolant leaks.

2. Swap Quality: The Single Most Important Factor:

   • Who Performed the Swap? Was it a professional shop specializing in such conversions, or a DIY backyard project? Ask for documentation, photos of the build process, and receipts.
   • Wiring: This is often the weakest link in a swap. Look for clean, properly routed, and insulated wiring. Avoid exposed wires, electrical tape "fixes," or a spaghetti-like mess.
   • Motor Mounts: Are they custom fabricated or off-the-shelf? Are they robust and properly aligned?
   • Cooling System: Is the radiator adequately sized for the diesel engine’s heat output? Are the fan and shroud properly installed? Overheating is a common issue with poorly designed cooling systems in swaps.
   • Fuel System: Are the fuel lines properly routed and secured? Is there a proper fuel filter setup?
   • Exhaust System: Is it custom fabricated? Does it clear all components? Is it properly hung to prevent rattling?
   • Transmission Mating: How was the engine mated to the transmission? Is there an adapter plate? Check for leaks or unusual noises during shifting.
   • Driveshafts: Were they modified or replaced to accommodate the new engine/transmission length? Check U-joints and balance.

3. Chassis & Body Condition:

   • Rust: Comanches are prone to rust, especially in the frame rails, rocker panels, floorboards, and bed mounts. Thoroughly inspect underneath the vehicle.
   • Suspension and Steering: Has the suspension been upgraded to handle the heavier diesel engine? Check for worn bushings, tie rods, and ball joints.
   • Frame Integrity: Look for cracks, repairs, or signs of stress, particularly around the motor mounts.

4. Legal & Emissions Considerations:

   • State Regulations: Engine swap laws vary significantly by state. Some states require the swapped engine to meet the emissions standards of the original vehicle’s model year, while others require it to meet the standards of the donor engine’s model year. Some states are more lenient if the engine is older than a certain year (e.g., pre-1975).
   • Registration and Ensure the title is clean and that the vehicle can be legally registered in your state with the swapped engine. This can be a major headache if not handled correctly.

5. Documentation:

   • Ask for all available documentation: receipts for parts, service history for the engine, details of the swap, and any build threads or photos. The more transparent the seller, the better.

Where to Find a Diesel Jeep Comanche For Sale

Finding a Diesel Jeep Comanche isn’t as simple as searching local dealership lots. These are niche vehicles found in niche places:

• Online Marketplaces: Craigslist, Facebook Marketplace, and eBay Motors are common platforms. Use specific search terms like "Diesel Comanche," "Cummins Comanche," "OM617 Jeep," etc.
• Specialty Forums and Groups: The Jeep Comanche Club forum (ComancheClub.com) is an invaluable resource. Look for "for sale" sections. Similarly, diesel swap forums (e.g., 4BTswaps.com, various Mercedes diesel forums) often have classifieds.
• Auction Sites: High-quality, professionally built diesel Comanches occasionally appear on enthusiast auction sites like Bring a Trailer or Cars & Bids.
• Word-of-Mouth: Network within the Jeep and off-road communities. Many of these unique builds change hands through personal connections.
• Custom Build Shops: Some shops specialize in engine swaps. They might have builds for sale or know of clients looking to sell.

Inspecting a Potential Purchase: A Buyer’s Checklist

Once you’ve found a promising candidate, follow these steps for a thorough inspection:

1. Pre-Purchase Inspection (PPI): This is non-negotiable. Have a trusted mechanic, ideally one familiar with engine swaps and diesel engines, perform a comprehensive inspection.
2. Cold Start Test: Always insist on a cold start. Listen for excessive cranking, unusual smoke, or rough idle.
3. Test Drive:
   • Check for smooth acceleration, proper shifting (manual or automatic), and responsive braking.
   • Listen for unusual noises (clunks, grinding, squeals) from the drivetrain, suspension, or steering.
   • Pay attention to vibration levels. Some diesel engines inherently vibrate more, but excessive vibration could indicate poor motor mounts or drivetrain issues.
   • Check all gauges, especially temperature and oil pressure.
4. Under the Hood:
   • Inspect all fluid levels and check for leaks.
   • Examine the quality of the custom fabrication: welds, routing of lines and wires, fitment of components.
   • Check belts and hoses for wear.
   • Look for signs of recent "cover-ups" (e.g., freshly painted components to hide leaks).
5. Under the Vehicle:
   • Thoroughly inspect the frame for rust, cracks, or botched repairs.
   • Check the condition of the fuel tank and fuel lines.
   • Examine the driveshafts, U-joints, axles, and transfer case.
6. Interior:
   • Verify all original and custom gauges work correctly.
   • Check the functionality of the heater, AC (if equipped), and electrical accessories.

Pricing a Diesel Jeep Comanche: What to Expect

Pricing a Diesel Jeep Comanche is highly subjective due to their custom nature. There’s no Kelley Blue Book value for a swapped vehicle. Prices can range dramatically based on:

• Engine Type: A Cummins 4BT swap generally commands a higher price than an OM617 due to engine cost and complexity.
• Swap Quality: A professional, well-documented swap from a reputable builder will be significantly more valuable than a "garage job" with questionable workmanship.
• Overall Condition: A rust-free body, clean interior, and well-maintained chassis will always fetch a premium.
• Modifications: Additional upgrades like lift kits, upgraded axles, custom bumpers, or high-end interiors will add value.
• Mileage: Both chassis and engine mileage play a role.

Expect prices to vary widely, from a few thousand dollars for a rough project with a basic swap to $20,000-$40,000+ for a meticulously built, show-quality example. Be prepared to pay for quality and craftsmanship.

Practical Advice and Actionable Insights

• Patience is a Virtue: These vehicles are rare. Don’t rush into a purchase.
• Quality Over Engine Type: A perfectly executed OM617 swap is far superior to a poorly done 4BT swap. Prioritize the quality of the build over the specific engine.
• Budget for the Unexpected: Even with a thorough inspection, a custom vehicle may present unforeseen issues. Set aside a contingency fund for post-purchase maintenance or improvements.
• Join the Community: Engage with Comanche and diesel swap forums. Ask questions, learn from others’ experiences, and potentially find leads on vehicles for sale.
• Know Your Local Laws: Before seriously pursuing a purchase, understand your state’s regulations regarding engine swaps, emissions, and vehicle registration.

Price Table: Estimated Ranges for Diesel Jeep Comanche For Sale

Given the custom nature of these vehicles, the following table provides estimated price ranges based on typical build quality and engine types. These are not definitive values but rather a guide to help set expectations.

Engine Type	Swap Quality	Overall Condition	Estimated Price Range (USD)	Key Considerations
Mercedes OM617	Basic DIY/Rough	Fair/Rust Present	$5,000 – $10,000	May require significant work; wiring/cooling issues common; good project base.
Mercedes OM617	Good DIY/Pro-Assisted	Good/Minor Flaws	$10,000 – $18,000	Solid runner, generally reliable; some aesthetic or minor mechanical improvements.
Mercedes OM617	Excellent Pro Build	Excellent/Show-Ready	$18,000 – $25,000+	Turn-key, refined, reliable; well-sorted; highly desirable.
Cummins 4BT	Basic DIY/Rough	Fair/Rust Present	$8,000 – $15,000	Potential for major issues (vibration, mounting); heavy engine; often loud.
Cummins 4BT	Good DIY/Pro-Assisted	Good/Minor Flaws	$15,000 – $25,000	Good power, may have manageable NVH (Noise, Vibration, Harshness); solid workhorse.
Cummins 4BT	Excellent Pro Build	Excellent/Show-Ready	$25,000 – $40,000+	Highly capable, well-engineered; quieted as much as possible; premium build.
VW TDI (various)	Basic DIY/Rough	Fair/Rust Present	$7,000 – $14,000	Electrical/tuning issues common; may lack heavy-duty feel; smaller engine.
VW TDI (various)	Good DIY/Pro-Assisted	Good/Minor Flaws	$14,000 – $22,000	Efficient, refined; good daily driver potential; check electronics thoroughly.
VW TDI (various)	Excellent Pro Build	Excellent/Show-Ready	$22,000 – $30,000+	Seamless integration, excellent economy; modern feel; for specific buyers.
Other Diesels	Variable	Variable	$10,000 – $35,000+	Price depends heavily on specific engine, complexity, and build quality.

Note: Prices are estimates and can fluctuate based on market demand, regional differences, and specific vehicle features/upgrades.

Frequently Asked Questions (FAQ) about Diesel Jeep Comanche For Sale

Q1: Were factory diesel Jeep Comanches sold in the US?
A1: No, factory diesel Jeep Comanches were never officially sold in the North American market. Any Diesel Comanche you find for sale will be an aftermarket engine swap.

Q2: What’s the best diesel engine for a Comanche swap?
A2: There’s no single "best" engine; it depends on your priorities.

• Mercedes OM617: Best for reliability, simplicity, ease of maintenance, and mechanical injection.
• Cummins 4BT: Best for raw power, torque, and heavy-duty use, but heavier and noisier.
• VW TDI: Best for fuel efficiency and a more refined, modern driving experience, but more complex electronically.

Q3: Are diesel engine swaps legal in all states?
A3: No. The legality of engine swaps varies significantly by state. Some states have strict emissions regulations that make swaps difficult or impossible, especially for newer vehicles. Always research your local Department of Motor Vehicles (DMV) or environmental protection agency’s regulations before purchasing. Generally, the swapped engine must meet the emissions standards of either the original chassis year or the donor engine year, whichever is more stringent.

Q4: How much does a professional diesel swap typically cost?
A4: A professional diesel engine swap can be very expensive, ranging from $10,000 to $30,000 or more, depending on the engine, desired level of refinement, and shop labor rates. This cost is usually factored into the selling price of a completed vehicle.

Q5: What are the most common issues with diesel-swapped Comanches?
A5: Common issues often stem from the swap quality:

• Wiring problems: Poorly executed electrical connections.
• Cooling issues: Inadequate radiator size for the diesel engine.
• Vibration and noise: Especially with the 4BT, if not properly mitigated.
• Transmission mating issues: Compatibility and adapter plate problems.
• Rust: The original Comanche chassis is prone to rust, which can be exacerbated by neglect.

Q6: Can a diesel-swapped Comanche be a reliable daily driver?
A6: Yes, a well-executed diesel swap can result in a very reliable daily driver. However, a poorly done swap can be a constant source of headaches. Thorough inspection and understanding the build quality are crucial for daily driver potential.

Q7: Is it cheaper to buy a swapped Comanche or build one myself?
A7: It’s almost always cheaper to buy a completed, well-done swapped Comanche than to build one yourself from scratch, especially if you factor in the cost of your time and potential mistakes. Building one is a labor of love, not a cost-saving measure.

Conclusion

The Diesel Jeep Comanche For Sale represents a unique proposition in the automotive world: a beloved classic truck infused with the robust, torquey, and efficient power of a diesel engine. For the discerning buyer, it offers a distinct blend of utility, capability, and character that few other vehicles can match.

However, the journey to owning one requires careful consideration and thorough due diligence. Since these are almost universally custom-built vehicles, the quality of the engine swap is paramount. By understanding the different engine options, knowing what to look for during inspection, and being aware of the legal and financial implications, you can navigate this niche market successfully. The effort is often well worth it, leading to ownership of a truly unique and capable machine – a testament to the enduring legend of the Jeep Comanche and the ingenuity of its passionate owners.